Multimodality imaging of developmental splenic anomalies: tips and pitfalls

A large gastric splenosis mimicking gastrointestinal stromal tumor: A case report and literature review

Splenosis pertains to the phenomenon wherein a segment of the spleen undergoes detachment and becomes embedded in other anatomical regions subsequent to traumatic rupture or therapeutic resection, and then progressively establishing blood circulation to foster the regeneration of splenic tissue. Existing literature posits that splenosis predominantly manifests within the confines of the abdominal and pelvic cavities. The objective of the current study was to present an uncommon case involving the occurrence of splenosis within the gastric myometrium, thereby contributing to the current knowledge regarding splenosis. A 16-year-old female sought medical assistance owing to recurrent abdominal pain persisting for a duration of six months, and had a history of splenectomy two years prior. Gastroscopy, endoscopic ultrasound and computed tomography (CT) examination collectively identified a lesion in the submucosal prominence of the fundus of the stomach. Initial considerations based on imaging examinations leaned towards a gastrointestinal stromal tumor. Consequently, an endoscopic resection was undertaken. Remarkably, the pathological findings and histochemistry concurred with the alterations associated with ectopic spleen implantation, leading to a stable postoperative course. In conclusion, splenosis denotes the implantation of a segment of the spleen into extraneous anatomical sites, attributable to traumatic rupture or therapeutic resection. The preoperative diagnosis of splenosis can pose a challenge, potentially culminating in unnecessary radical clinical interventions. Therefore, the acquisition of a comprehensive medical history, with a particular focus on surgical and trauma events, emerges as pivotal for an accurate diagnosis. In light of novel diagnostic modalities, the non-invasive technology of nuclear medicine can efficaciously visualize ectopic splenic tissue, thereby averting superfluous surgical procedures. It is both feasible and imperative to implement individualized treatment strategies for patients afflicted with splenosis.

Wandering spleen in a postpartum female: a case report

Introduction and importance

Wandering spleen (WS) is a rare condition that occurs when the spleen is not in its normal anatomical location, but in the abdominal or pelvic cavity. The mechanism of this condition may be due to dysfunction of ligaments that fixate the spleen in its position. Female hormonal alterations during pregnancy and other unknown causes in children may also play role in an ectopic spleen.

Case presentation

The authors report a case of a 34-year-old woman who presented to the emergency department with intermittent abdominal pain that persisted after childbirth without other symptoms.

Clinical discussion

Clinically the symptoms are varied and abdominal pain is the most common presentation. Radiological investigation of WS include ultrasound, MRI, and CT, which is the most preferred tool. Treatments after the diagnosis include splenectomy or splenopexy either through laparoscopy or laparotomy.

Conclusion

Physicians should include ectopic spleen as a differential diagnosis in a multiparous woman with the presentation of acute or chronic abdominal pain.

Diagnostic accuracy of apparent diffusion coefficient to differentiate intrapancreatic accessory spleen from pancreatic neuroendocrine tumors

BACKGROUND

Intrapancreatic accessory spleen (IPAS) shares similar imaging findings with hypervascular pancreatic neuroendocrine tumors (PNETs), which may lead to unnecessary surgery.

AIM

To investigate and compare the diagnostic performance of absolute apparent diffusion coefficient (ADC) and normalized ADC (lesion-to-spleen ADC ratios) in the differential diagnosis of IPAS from PNETs.

METHODS

A retrospective study consisting of 29 patients (16 PNET patients vs 13 IPAS patients) who underwent preoperative contrast-enhanced magnetic resonance imaging together with diffusion-weighted imaging/ADC maps between January 2017 and July 2020 was performed. Two independent reviewers measured ADC on all lesions and spleens, and normalized ADC was calculated for further analysis. The receiver operating characteristics analysis was carried out for evaluating the diagnostic performance of both absolute ADC and normalized ADC values in the differential diagnosis between IPAS and PNETs by clarifying sensitivity, specificity, and accuracy. Inter-reader reliability for the two methods was evaluated.

RESULTS

IPAS had a significantly lower absolute ADC (0.931 ± 0.773 × 10^-3 mm²/s vs 1.254 ± 0.219 × 10^-3 mm²/s) and normalized ADC value (1.154 ± 0.167 vs 1.591 ± 0.364) compared to PNET. A cutoff value of 1.046 × 10^-3 mm²/s for absolute ADC was associated with 81.25% sensitivity, 100% specificity, and 89.66% accuracy with an area under the curve of 0.94 (95% confidence interval: 0.8536-1.000) for the differential diagnosis of IPAS from PNET. Similarly, a cutoff value of 1.342 for normalized ADC was associated with 81.25% sensitivity, 92.31% specificity, and 86.21% accuracy with an area under the curve of 0.91 (95% confidence interval: 0.8080-1.000) for the differential diagnosis of IPAS from PNET. Both methods showed excellent inter-reader reliability with intraclass correlation coefficients for absolute ADC and ADC ratio being 0.968 and 0.976, respectively.

CONCLUSION

Both absolute ADC and normalized ADC values can facilitate the differentiation between IPAS and PNET.

PET/CT of the Spleen with Gallium-Oxine-Labeled, Heat-Damaged Red Blood Cells: Clinical Experience and Technical Aspects

Several scintigraphic techniques have been supplemented or replaced by PET/CT methods because of their superior sensitivity, high resolution, and absolute activity quantification capability. The purpose of this project was the development of a PET tracer for splenic imaging, its radiopharmaceutical validation, and its application in selected patients in whom unclear constellations of findings could not be resolved with established imaging methods. Heat-damaged red blood cells (RBCs) were labeled with [⁶⁸Ga]gallium-oxine, which was produced from [⁶⁸Ga]gallium and 8-Hydroxyquinoline (oxine) on an automated synthesizer. Ten patients underwent [⁶⁸Ga]gallium-oxine-RBC-PET/CT for the classification of eleven unclear lesions (3 intra-, 8 extrapancreatic). [⁶⁸Ga]gallium-oxine and [68Ga]gallium-oxine-labeled RBCs could be synthesized reproducibly and reliably. The products met GMP quality standards. The tracer showed high accumulation in splenic tissue. Of the 11 lesions evaluated by PET/CT, 3 were correctly classified as non-splenic, 6 as splenic, 1 as equivocal, and 1 lesion as a splenic hypoplasia. All lesions classified as non-splenic were malignant, and all lesions classified as splenic did not show malignant features during follow-up. PET/CT imaging of the spleen with [⁶⁸Ga]gallium-oxine-labeled, heat-damaged RBCs is feasible and allowed differentiation of splenic from non-splenic tissues, and the diagnosis of splenic anomalies.

High-Resolution Splenic Imaging: [68Ga]Ga-Oxine Red Blood Cell PET/CT for Differentiation of Splenosis Mimicking Malignant Lymphoma

The differentiation of splenic tissue from malignant lesions via imaging may be challenging, particularly considering aberrant or accessory lesions and diseases that are rarely encountered. Functioning splenic tissue can be identified using technetium-99m red blood cell (^99mTc-RBC) scintigraphy, but its sensitivity is limited and may not be available. We present the case of a patient in whom disseminated abdomino-pelvic splenosis was diagnosed using PET/CT with gallium-68-oxine-labeled RBCs. The method represents a feasible and probably superior alternative to splenic scintigraphy.